How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
False: IP = PSPACE needs no degree reduction in this arithmetization
Statement
False assertion. If the multilinearization operators are omitted from the quantified arithmetization and the resulting protocol uses only the quantifier operators and in inner-to-outer order, then the prover messages still have degree polynomial in the input length: for every closed prenex quantified Boolean formula of size , the polynomial carried at every operator node of the naive sequence has degree at most a polynomial in , so no degree reduction is needed for this proof route.
Facts & Assumptions
Given: The naive inner-to-outer quantified arithmetization without multilinearization operators, and the family of formulas defined below.
The ordered arithmetization replaces NOT, AND and OR by , and , applies to a universally quantified variable and to an existentially quantified variable, and processes inner quantifiers first (Field arithmetization of QBF quantifiers).
The multilinearized ordered arithmetization inserts, before each quantifier operation, the reductions ; the variant considered here omits exactly these reductions and keeps the same quantifier operations and the same inner-to-outer order (Multilinearization in one variable).
A closed prenex quantified Boolean formula is with quantifier-free matrix , and its truth value is defined by the usual Boolean semantics of the quantifiers over (Quantified Boolean formulas and the language TQBF).
Arithmetization maps a variable leaf to and a matrix built from these leaves by the gate rules of [A1] (Arithmetization of Boolean formulas).
Refutation
For every let ; its matrix is the variable , and its prefix has quantifiers. Fix the standard effective encoding with binary variable indices and fixed punctuation, so the encoded size of this family is . By [A4] the arithmetization of the matrix is .
In the naive inner-to-outer sequence the universal quantifiers are processed first, starting with the innermost and ending with , and the outer existential quantifier in is processed last, by the ordering rule of [A1]; the omitted operations are precisely the reductions of [A2].
We claim that after the first universal quantifiers the carried polynomial is , by induction on . For this is ; for the step, does not involve the next variable , so both of its specializations at and equal , and gives the product .
Taking in step 2.1, the polynomial carried at the input of the outer quantifier node is , whose degree as a polynomial in the active variable is ; the message that the protocol requires at that node is the restriction of this polynomial in the active variable, so it also has degree .
Since for the encoding fixed in step 1.1, every polynomial is bounded above by a polynomial in and is eventually smaller than . Hence the asserted polynomial degree bound fails for the family under this allowed encoding, which refutes the false assertion. The count of syntax nodes alone would not give this encoded-length bound under an arbitrary effective encoding.
The failure is one of degree and not of Boolean semantics: for every the formula is true, because holds exactly when and then is satisfied; so the refuted degree bound is not rescued by any appeal to the truth of the instances.
Depends on
Used by
- Exponential degree without multilinearization Counterexample
Dependency tree · two levels
6 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- Arora and Barak, Computational Complexity: A Modern Approach, §8.5.3 (degree growth warning) and Remark 8.19, author-hosted draft (standard reference, not scraped)
- A. Shen, IP = PSPACE: Simplified Proof, JACM 39(4) 1992, pp. 878–880 (standard reference, not scraped)